Method and apparatus for producing a master disc on which digital data is recorded in synchronism with pre-recorded address data

ABSTRACT

A recording medium on which digital data is recorded in synchronism with pre-recorded address data. At least a portion of the address data is converted in accordance with a pre-set conversion rule.

This application is a continuation of application Ser. No. 09/649,955filed Aug. 29, 2000 now U.S. Pat. No. 6,985,410.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a recording medium, a method and apparatus forpreparing a master disc for a recording medium, a method and apparatusfor recording a recording medium, a method and apparatus for reproducinga recording medium and a disc-shaped recording medium. Moreparticularly, it relates to a recording medium on which address datahave been recorded at the outset, a method and apparatus for preparing amaster disc for the recording medium, a method and apparatus forrecording the recording medium, a method and apparatus for reproducingthe recording medium, and a disc-shaped recording medium.

2. Background of the Invention

As a recording medium having optically recorded thereon digital data,such as high-quality digital video signals, there has widely been knowna replay-only DVD (digital versatile disc or a digital video disc).Recently, attempts are being made for commercialization or developmentof a DVD-R (DVD-Recordable), a DVD-RW (DVD-Rewritable) or a DVD-RAM(DVD-Random Access memory), as a write-once or rewritable recordingmedium exploiting the DVD format.

In these recording mediums, as in the CD-R (CD-Recordable), CD-RW(CD-Rewritable) or MO (magneto-optical) disc, grooves or pre-pits arerecorded sequentially as address data are incremented.

Meanwhile, in the above-described recording medium, a blank disc, onwhich main data are not recorded as yet, address data are determineddefinitely. Thus, there has persisted a risk of illicitly copying thecontents of the recording medium bit-by-bit or falsifying critical data,such as copyright data, recorded on the specified address data.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide recordingmedium which resolves the above-mentioned problem.

It is another object of the present invention to provide an apparatusfor preparing a master disc for a recording medium which resolves theabove-mentioned problem.

It is a further object of the present invention to provide a method forpreparing a master disc for a recording medium which resolves theabove-mentioned problem.

It is a further object of the present invention to provide a recordingapparatus for a recording medium which resolves the above-mentionedproblem.

It is still another object of the present invention to provide arecording method for a recording medium which resolves theabove-mentioned problem.

It is yet another object of the present invention to provide areproducing apparatus for a recording medium which resolves theabove-mentioned problem.

It is a further object of the present invention to provide a reproducingmethod for a recording medium which resolves the above-mentionedproblem.

It is another object of the present invention to provide a disc-shapedrecording medium which resolves the above-mentioned problem.

According to the present invention, there is provided a recording mediumon which digital data has been recorded in synchronism with pre-recordedaddress data wherein at least a portion of the address data has beenrecorded on conversion on the basis of a pre-set conversion rule.

According to the present invention, there is provided an apparatus forpreparing a master disc of a recording medium on which digital data isrecorded in synchronism with pre-recorded address data, in which theapparatus includes pre-format signal generating means for generatingpre-format signals pre-recorded on the recording medium, the pre-formatsignals containing the address data, and recording means for recordingthe pre-format signals from the pre-format signal generating means onthe master disc. The pre-format signal generating means converts atleast a portion of the address data in accordance with a pre-setconversion rule to generate the pre-format signals.

According to the present invention, there is provided a method forpreparing a master disc used for preparing a recording medium on whichdigital data has been recorded in synchronism with pre-recorded addressdata, in which the method includes converting at least a portion of theaddress data based on a pre-set conversion rule, generating pre-formatsignals for recording on the master disc, the pre-format signalscontaining the address data and recording the generated pre-formatsignals on the master disc.

According to the present invention, there is provided an apparatus forrecording digital data on a recording medium in synchronism withpre-recorded address data, the apparatus including recording signalgenerating means for generating recording signals to be recorded on therecording medium. The recording signal generating means detects an areain the recording medium where at least a portion of the address data isrecorded on conversion in accordance with a pre-set conversion rule. Therecording signal generating means decodes the converted address datapre-recorded in the area to generate the recording signals in accordancewith the decoded address data.

According to the present invention, there is provided a method forrecording digital data on a recording medium in synchronism withpre-recorded address data, in which the method includes detecting anarea of the recording medium where at least a portion of the addressdata is recorded on conversion in accordance with a pre-set conversionrule, decoding the converted address data pre-recorded in the area, andgenerating recording signals to be recorded on the recording medium inaccordance with decoded address data.

According to the present invention, there is provided a disc-shapedrecording medium including a first area in which data is to be recorded,and a second area in which is recorded the information at leastincluding the control information required for reproducing data recordedin the first area, wherein address data are pre-recorded in the firstand second areas; at least a portion of the address data of the secondarea is converted in accordance with a pre-set conversion rule.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic structure of a disc-shaped recordingmedium according to the present invention.

FIG. 2 illustrates the block structure of data in the DVD format.

FIG. 3 illustrates a sector structure in recording.

FIG. 4 illustrates the physical structure of a disc-shaped recordingmedium in the DVD-R and DVD-RW.

FIG. 5 illustrates the physical structure of a disc-shaped recordingmedium in the DVD-RAM.

FIG. 6 illustrates the physical structure of a disc-shaped recordingmedium in the CD-R and CD-RW.

FIG. 7 illustrates the sequence of manufacturing a disc-shaped recordingmedium shown in FIG. 1.

FIG. 8 is a block diagram for illustrating the structure of a masteringdevice according to the present invention.

FIG. 9 is a block diagram for illustrating the structure of a datarecording apparatus according to the present invention.

FIGS. 10A and 10B illustrate illicit copying in which the data recordingstart position is offset to effect recording, FIG. 10A showing arecording track for an original disc-shaped recording medium and FIG.10B showing a recording track for a disc-shaped recording medium ontowhich data is to be copied.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, preferred embodiments according to thepresent invention will be explained in detail.

The preferred embodiments of the present invention comprise adisc-shaped recording medium, which is an unrecorded or blank disc, suchas DVD-R (DVD-Recordable), DVD-RW (DVD-Rewritable) or DVD-RAM(DVD-Random Access memory) for writing only once or overwriting, as arecording medium employing the so-called DVD (digital versatile disc ora digital video disc) format, or CD-R (CD-Recordable) or CD-RW(CD-Rewritable), as a recording medium employing the CD (Compact Disc),a mastering device as an apparatus for preparing master discs of theserecording mediums, and a recording apparatus for recording data on thesedisc-shaped recording mediums.

A disc-shaped recording medium 1, shown in FIG. 1, includes a recordingarea 2 for main data, a so-called lead-in area 3, arranged on the innerrim side, and a so-called lead-out area 4, arranged on the outer rimside. An area 5 is an optional area on the disc-shaped recording medium1 including, for example, a beginning portion of the recording area 2towards the inner rim side. It is unnecessary for the area 5 to includethe lead-in area 3 or the lead-out area 4. In this area 5, there arerecorded the control information indispensable for reproducing datarecorded in the recording area 2, copyright information and theinformation for decoding encrypted data. In addition, the discriminatinginformation indicating the presence of the area 5 is recorded in e.g.,the lead-in area 3 of the disc-shaped recording medium 1.

The block structure of data in the DVD format is hereinafter explained.The data block structure in the DVD format is of a so-called productcode structure in which two error correction codes, namely PI in the rowdirection and PO in the column direction, are added to 2064×16sectors=33024 byte data, as shown for example in FIG. 2. The PI is a(182, 172, 11) Reed-Solomon code and PO is a (208, 192, 17) reed-Solomoncode. In the DVD, the PO codes in the block so formed are divided on thebyte basis to each sector to provide 16 recording sectors, as shown inFIG. 3.

Each recording sector is made up of a 4-byte ID, in a portion of which asector address is recorded, a 2-byte IEC, as an ID error check code, a6-byte RSV, as the control information, 2048 byte main data, 4-byte EDC,as the error check code, a 120-byte EDC and a 182-byte PO. Of the182-byte PO, 10 bytes, shown shaded in FIG. 3, may also be used as thePI.

In the DVD, these data are 8-16 demodulated and synchronization signalsare appended to the modulated data. The resulting data is recorded aspits in a disc-shaped recording medium.

In the above-described DVD-R, DVD-RW and DVD-RAM, data is recorded onthe disc-shaped recording medium by thermal recording employing anorganic dye material or by phase changes between the crystalline phaseand the amorphous phase employing a phase-change recording material,basically in accordance with the DVD format. The physical structure ofthe disc-shaped recording medium in the DVD-R and DVD-RW is such thatplural grooves wobbled at a period of approximately 140 kHz in a radialdirection of the disc-shaped recording medium and land pre-pits (LPP)comprising address data as pre-pits are arranged alternately in theradial direction of the disc-shaped recording medium, as shown in FIG.4. In the grooves, data are recorded as pits. On the other hand, thephysical structure of the disc-shaped recording medium in the DVD-RAM issuch that plural grooves wobbled at a period of approximately 160 kHz ina radial direction of the disc-shaped recording medium and lands arealternately arranged in the radial direction of the disc-shapedrecording medium with intermission, as shown in FIG. 5. There isprovided a header in a mirror portion between the grooves and the lands.In the header are recorded addresses as embossed pits. In the groovesand lands, data are recorded as changes between the crystalline phaseand the amorphous phase.

The physical structure of the disc-shaped recording medium in the CD-Rand CD-RW is such that plural pre-grooves wobbled at a period ofapproximately 22 kHz in a radial direction of the disc-shaped recordingmedium and lands are arranged alternately in the radial direction of thedisc-shaped recording medium, as shown in FIG. 5. Address data arerecorded in the pre-grooves themselves as frequency modulated ATIP(absolute time in pre-groove). In the pre-grooves, data are recorded aspits or as changes between the crystalline phase and the amorphousphase.

In these disc-shaped recording mediums, 20 to 64 bit address data aresequentially recorded in a pre-set sequence. Meanwhile, in theabove-mentioned disc-shaped recording mediums, not all address data arerecorded in the serial sequence. Specifically, track numbers and sectornumbers may be separated from one another, or the address data may beseparated into minute, second or frame numbers. However, the addressdata may be deemed to be incremented in accordance with a pre-set rule.

In the following, the address data previously recorded in the pre-pits,emboss marks or pre-grooves of the disc-shaped recording medium, that isrecorded in pre-formatting, and address data of data, such as sectoraddresses or block addresses, as shown in FIGS. 4 through 6, are termedpre-address data and post address data, respectively, in order todistinguish these two sorts of the address data.

In the above-described disc-shaped recording medium 1, pre-address data,to be recorded in a pre-set sequence in an ordinary case by a masteringdevice, as later explained, are recorded at least in a pre-set area,such as area 5, after conversion in accordance with a pre-set conversionrule. That is, in the disc-shaped recording medium, the pre-address datain the area 5 is converted in accordance with a pre-set conversion ruleand recorded after this conversion, instead of being sequentiallyrecorded in the grooves or pre-pits in an incrementing order.

For example, if the sectors 128 (0000000010000000) to 32767(0111111111111111) represent the area 5, the pre-set conversion rule maybe defined by the following methods:

As the first method, the sector addresses, which should be sequentiallyrecorded in an incrementing order of 128, 129, 130, . . . , 32766,32767, are recorded in a decrementing order. That is, in the disc-shapedrecording medium 1, the sector addresses of the area 5 are sequentiallyrecorded in a decrementing order of 32767, 32766, . . . , 130, 129, 128.

As the second method, applied to a case in which the entire sectoraddresses are represented by the 15-bit information, such as 128, 129,130, . . . , 32766, 32767, the entire 16-bit information is notconverted, but the information corresponding to the lower 15 bits isrewritten by an optional method. If the lower 15-bit information is notrewritten unexceptionally, but the entire address data to be convertedare represented by an optional number of bits less than 16 bits, it ispossible to rewrite only the information corresponding to the number ofbits. On the disc-shaped recording medium 1, the informationrespectively rewritten from sector addresses 128, 129, 130, . . . ,32766, 32767 is recorded in the area 5.

As a third method, 16-bit M series are generated and added to the sectoraddresses 128, 129, 130, . . . , 32766, 32767. A generating polynominalof this 16-bit M-series is represented by, for example,g(x)=x ¹⁶ +x ¹² +x ⁵+1.In the disc-shaped recording medium 1, the first data of the M-series isa secret key for decoding the converted addresses. In the disc-shapedrecording medium 1, the information converted respectively from sectoraddresses 128, 129, 130, . . . , 32766, 32767 are recorded in the area5.

As a fourth method, the sector addresses 128, 129, 130, . . . , 32766,32767 are encrypted by, for example, DES (data encryption standard). Inthe DES, 56-bit data are used as an encryption key. In the disc-shapedrecording medium 1, a pre-set bit string is added to each of the sectoraddresses 128, 129, 130, . . . , 32766, 32767 to generate a key. Theinformation converted from the sector addresses 128, 129, 130, . . . ,32766, 32767 is recorded in the area 5 of the disc-shaped recordingmedium 1.

Meanwhile, in the disc-shaped recording medium 1, an encryption key maybe recorded in a pre-set area for address data of the disc-shapedrecording medium 1, such as in a sector 127. If data including main datais recorded in the pre-set area by a data recording apparatus, as laterexplained, an encryption key may also be recorded in the data sector.Moreover, a code of a producer of the disc-shaped recording medium or anID of the disc-shaped recording medium 1 may be substituted for part orall of the encryption key.

This disc-shaped recording medium 1 is manufactured by a sequence shownin FIG. 7. That is, a photoresist, as a photosensitive material, iscoated on a glass substrate in a resist coating step 11. In a cuttingstep, laser cutting is performed on the glass substrate, coated with thephotoresist, using a light beam modulated based on data to bepre-formatted. In this laser cutting step S12, a light beam isilluminated on the photoresist of the glass substrate, to effectpre-formatting, depending on the sort of the disc-shaped recordingmedium 1, as shown in FIGS. 4 through 6. At this time, pre-address dataare recorded and formed on the photoresist of the glass substrate. Then,laser cutting of the photoresist on the glass substrate is performed inaccordance with pre-format signals for recording pre-address dataconverted in accordance with the above-described pre-set conversionrule. In a developing/fixing step 13, the laser-cut photoresist of theglass substrate is developed and fixed. In a metal master disc producingstep 14, the surface of the photoresist is electro-plated to produce ametal master disc. The above-described sequence of operations isperformed by a mastering device as later explained to prepare a masterdisc, that is a master of the disc-shaped recording medium 1.

Then, in a stamper step 15 and in a substrate forming step 16, a stamperis prepared, using the stamper. The produced stamper is mounted on aninjection molding device where a substrate is produced by injectionmolding using an optically transparent resin, such as polycarbonate (PC)or acrylic resin. In a reflective film forming step 17, a reflectivefilm is formed by sputtering on one of the major surfaces of the moldedtransparent resin. For this sputtering, a target formed of a materialusable for forming a special recordable reflective film is used. Forexample, such a material is used which is mainly formed of Ar or Al, hasa reflectance of the same order of magnitude as that of the routine CDor DVD or a reflectance that permits readout with a routine optical headand that is capable of forming a special reflective film which causesthe reflectance to be changed by illuminating the laser of a powerhigher than that of the laser used in reproduction on the so-formedspecial reflective film. In a protective film coating step S18, a UVlight curable resin is coated on the reflective film and UV light isilluminated on the UV light curable resin to form a protective film.

Thus, in the disc-shaped recording medium 1, a master disc is preparedby a mastering device and used to prepare a stamper to manufacture ablank disc. The mastering device is hereinafter explained.

Referring to FIG. 8, a mastering device 20, given only by way of anexample, includes a light source 21, for example, a gas laser, e.g., anAr ion laser, a He—Cd laser or a Kr ion laser, a light modulator 22 formodulating (on/off controlling) the laser light radiated from therecording light source 41, based on a signal from a pre-format signalgenerator 25, as later explained, an optical pickup 23 having anobjective lens, a mirror etc for converging the laser light transmittedthrough the light modulator 22 for illuminating the laser light on aphotoresist surface of the glass substrate 29 coated with thephotoresist, and a servo circuit 24 for focussing the optical pickup 23for maintaining a constant distance between the optical pickup 23 and asubstrate 29 and for controlling the rotational driving operation of aspindle motor 28, as later explained. The mastering device 20 alsoincludes the pre-format signal generator 25 for generating pre-formatsignals recorded on the substrate 29, based on address data from anaddress data generator 26 and on an area specified by an addressconversion area specifying unit 27, as later explained, for turning thelight modulator 22 on and off, the address data generator 26 forgenerating address data, and the address conversion area specifying unit27 for converting a pre-address, that is the above-mentioned area 5. Themastering device 20 also includes a spindle motor 28 for rotationallydriving the substrate 29.

Meanwhile, this mastering device 20 is used mainly in theabove-mentioned cutting step 12. Finally, a master of the disc-shapedrecording medium 1 is to be prepared. Other components required in theremaining steps are not shown here.

In the mastering device 20, the laser light from the light source 21 ismodulated by the light modulator 22 in accordance with preformat signalsgenerated by the pre-format signal generator 25. The light modulator 22includes an EOM (electro-optical modulator), the refractive index ofwhich is changed with the applied electrical voltage, and an EOD(electro-optical deflector) for changing the polarization by the appliedvoltage. As the light modulator 22, an AOM (acousto-optical modulator)or an AOD (acousto-optical deflector) for generating ultrasonic wave(compressional wave) in a medium by a piezoelectric element. Themastering device 20 illuminates the modulated laser light through theoptical pickup 23 on a substrate 29 rotationally driven at e.g., a CLVor CAV, by the spindle motor 28, to effect pre-formatting, depending pnthe type of the disc-shaped recording medium 1, as described above, torecord pre-address data, as shown in FIGS. 4 through 6,

The pre-format signals, recorded by this mastering device 20 on thesubstrate 29, are generated by the pre-format signal generator 25. Thepre-format signal generator 25 includes an address comparator 31 forcomparing address data generated by the address data generator 26 to thearea specified by the address conversion area specifying unit 27, anaddress converter 32 for converting the pre-address by e.g., theabove-described method, and an address recorder 33 for controlling thelight modulator 22 and the servo circuit 24 for recording thepre-address on the substrate 29.

The pre-format signal generator 25 is fed with address data generated bythe address data generator 26 and with the information specifying thearea specified by the master producer through the address conversionarea specifying unit 27. The input information is recorded as preformatsignals in some area on the substrate 29. It is assumed here that theaddress data generator 26 sequentially generates address data in anincrementing fashion to output the generated address data to thepre-format signal generator 25. The pre-format signal generator 25compares the input address data to the specified area by the addresscomparator 31 to verify whether or not the input address data is theaddress data contained in the specified area, that is in theabove-mentioned area 5. For example, if the area 5 is provided on theinner rim side of the recording area 2, as shown in FIG. 1, it isverified whether the address data is smaller than the address dataspecifying the start position of the recording area 2. Alternatively,the address data is compared to the address data specifying the area 5stored in the memory in the pre-format signal generator 25 to verifywhether or not the address data is contained in the area 5.

If the input address data is not contained in the specified area, thepre-format signal generator 25 directly sends the input address data tothe address recorder 33.

On the other hand, if the input address data is contained in thespecified area, the pre-format signal generator 25 converts the inputaddress data, by the attitude and/or position prediction unit 32, inaccordance with the above-described pre-set conversion rule. Thepre-format signal generator 25 sends the converted pre-addressinformation to the address recorder 33.

The pre-format signal generator 25 generates preformat signals, derivedfrom converted or non-converted pre-address data, by the addressrecorder 33, to control the light modulator 22 or the servo circuit 24.

By so doing, the mastering device 20 records the converted ornon-converted pre-address data at pre-set positions, as the masteringdevice 20 forms the grooves or lands, depending on the sort of thedisc-shaped recording medium 1, on the substrate 29, to prepare a masterof the disc-shaped recording medium 1, as shown in FIGS. 4 through 6.

On the disc-shaped recording medium 1, which is a blank discmanufactured on the basis of the steps shown in FIG. 7, based on theso-produced master, the control information indispensable for datareproduction, copyright information, and source data, such as digitalvideo signals or digital audio signals, including the information fordecoding the encrypted data, can be recorded by a data recordingapparatus 40 shown in FIG. 9.

The data recording apparatus 40, shown in FIG. 9, includes a recordinglight source 41, as a gas laser, such as an Ar ion laser, a He—Cd laseror a Kr ion laser, or a semiconductor laser, a light modulator 42 formodulating (on/off controlling) the laser light radiated by therecording light source 41, based on a signal from a pre-format signalgenerator 45, as later explained, and an optical pickup 43 having anobjective lens, a mirror etc for converging the laser light transmittedthrough the light modulator 42 for illuminating the laser light on thedisc-shaped recording medium 1.

The data recording apparatus 40 also includes an optical pickup 44 forreproduction having an optical system for illuminating the laser lightfrom the reproducing light source, not shown, which is, for example, agas laser, such as a He—Ne laser, or a semiconductor laser, on thedisc-shaped recording medium 1, a servo circuit 45 for focussing therecording optical pickup 43 and the reproducing optical pickup 44 formaintaining a constant distance from the disc-shaped recording medium 1and for controlling the rotational driving operation of a spindle motor49 as later explained and a recording signal generator 46 for generatinga recording signal for recording on the disc-shaped recording medium 1based on the source data from a source data generator 47 as laterexplained and on sub-code data from a sub-code generator 47 as laterexplained and for turning the light modulator 42 on and off. Themastering device 20 also includes the source data generator 47 forgenerating the source data, a sub-code generator 48 for generatingso-called sub-code data and the spindle motor 49 for rotationallydriving the disc-shaped recording medium 1. The data recording apparatus40, shown in FIG. 9, includes the recording optical pickup 43 and thereproducing optical pickup 44 facing each other with the recordingmedium 1 in-between. However, the recording optical pickup 43 and thereproducing optical pickup 44 may be arranged on one side of therecording medium 1. Alternatively, a sole optical pickup may be used torecord data or read out address data. In the latter case, the outputlevel of the light source of the sole optical pickup is switched betweenthat for data recording and that for readout of address data.

The data recording apparatus 40 detects conversion of pre-address datarecorded on the disc-shaped recording medium, based on the pre-addressdata read out through the reproducing optical pickup 44 by the recordingsignal generator 46, to generate recording signals. Based on thegenerated recording signals, the data recording apparatus 40 modulatesthe laser light from the recording light source 41 by the lightmodulator 42. Similarly to the light modulator 22 in the masteringdevice 20, the light modulator 42 has an EOM and an EOD, or an AOM andan AOD. The data recording apparatus 40 illuminates the laser light,modulated by the light modulator 42, on the disc-shaped recording medium1, run in rotation by the spindle motor 49 at e.g., a CLV or CAV, fromthe recording optical pickup 43, to record e.g., digital video signalsor digital audio signals on the disc-shaped recording medium 1.

The recording signals, recorded by this data recording apparatus 40 onthe disc-shaped recording medium 1, are generated by a recording signalgenerator 46. The recording signal generator 46 includes an addressappending unit 51 for combining source data generated by the source datagenerator 47 and the sub-code data, inclusive of post address data,generated by the sub-code generator 48, to generate data having the postaddress data, appended thereto, and an address generator 52 forreproducing address data from the signals read out via the reproducingoptical pickup 44. The recording signal generator 46 also includes anaddress conversion area readout unit 53 for detecting and reading outthe area where pre-address data have been converted, that is theabove-mentioned area 5, based on the aforementioned conversion rule,from the signals read out through the reproducing optical pickup 44, andan address decoding unit 54 for decoding the information of thepre-address data reproduced by the address generator 52. The recordingsignal generator 46 also includes an address comparator 55 for comparingthe post address data appended to the data supplied from the addressappending unit 51 to the pre-address data decoded by the addressdecoding unit 54, and a data recording unit 56 for controlling the lightmodulator 42 and the servo circuit 45 for recording data on thedisc-shaped recording medium 1.

The recording signal generator 46 is fed with source data generated bythe source data generator 47 and with sub-code data inclusive of thepost-address data generated by the sub-code generator 48 to generatedata having the post address data appended thereto by the addressappending unit 51. The recording signal generator 46 is also fed with asignal read out from the disc-shaped recording medium 1 by thereproducing optical pickup 44 moved to a position above the disc-shapedrecording medium 1 in register with the appended post-address data toreproduce pre-address data from the read-out signals by the addressgenerator 52 to send the reproduced data to the address decoding unit54. In addition, the recording signal generator 46 detects and readsout, from the signal read out by the address conversion area readoutunit 53, whether or not the area in which the reproducing optical pickup44 is located is within the above-mentioned area 5. The recording signalgenerator 46 then sends a signal indicating the result to the addressdecoding unit 54.

The recording signal generator 46 then routes the data, generated onappendage of the post-address data by the address appending unit 51, tothe address comparator 55. The recording signal generator 46 alsodecodes the pre-address data, reproduced by the address generator 52, bythe address decoding unit 54,

The address decoding unit 54 effects decoding based on the signal fromthe address conversion area readout unit 53. That is, if the pre-addressdata supplied from the address generator 52, is outside the area 5, theaddress decoding unit 54 effects routine decoding. If conversely thepre-address data supplied from the address generator 52 is outside thearea 5, this pre-address data has been converted based on theaforementioned conversion rule. So, the address decoding unit 54 effectsdecoding in accordance with the above-mentioned conversion rule. Theaddress decoding unit 54 routes the pre-address data, obtained ondecoding, to the address comparator 55.

The recording signal generator 46 then compares, by the addresscomparator 55, the post-address data, appended to the data supplied fromthe address appending unit 51, to the pre-address data appended to thedata supplied from the address appending unit 51, to verify whether ornot the two address data are associated with each other.

If the two address data are not associated with each other, therecording signal generator 46 compares the post-address data to thepre-address data, reproduced and decoded from the signals read out froma different position on the disc-shaped recording medium 1 by thereproducing optical pickup 44, with the aid of the address comparator55.

If the two address data are associated with each other, the recordingsignal generator 46 sends data supplied from the address appending unit51 to the data recording unit 56, by which recording signals aregenerated to control the light modulator 42 and the servo circuit 45.

By so doing, the data recording apparatus 40 is able to record sourcedata at a pre-set position on the disc-shaped recording medium 1 throughthe recording optical pickup 43.

In this manner, the data recording apparatus 40 is aware of the dataconversion rule in the disc-shaped recording medium 1 so that sourcedata can be recorded on the disc-shaped recording medium 1 based on theconversion rule for the pre-address data. So, any illicit data recordingapparatus unaware of the pre-address data conversion rule or any illicitdata recording apparatus attempting to record data regardless of thepre-address data conversion rule has to discontinue data recordingbecause the pre-address data is not the pre-set incremented pre-addressdata and hence an address data error persists. That is, only theauthorized data recording apparatus 40 aware of the pre-address dataconversion rule is able to record data.

In recording data on the disc-shaped recording medium 1, the postaddress data, recorded in synchronism with the pre-addresses, aresequentially inputted to the data recording apparatus in an incrementingfashion, and are compared to the converted pre-address data, so that anyunauthorized data recording apparatus, attempting to record data byoffsetting the data recording start position, is unable to record dataon the disc-shaped recording medium 1, as shown in FIGS. 10A and 10B.

Assume that data recorded on a recording track of a marketed routineoriginal disc-shaped recording medium, such as a replay-only DVD, is tobe copied on a recording track of a different type of the disc-shapedrecording medium, such as DVD-R, DVD-RW or DVD-RAM. Moreover, assumethat data are recorded in an encrypted form on the original disc-shapedrecording medium and that the information for decryption is recorded ina copy inhibited area. In such case, an unauthorized data recordingapparatus is able to perform illicit copying by providing a datarecording start position, that is a start address, in an area downstreamof the area in which to record the information for decryption, to givean offset to the address data, such as to evade the copy inhibited area.

However, since the pre-address data is converted in the disc-shapedrecording medium 1, it is possible for simple address data offsetting toresult in failure in copying even if an unauthorized data recordingapparatus attempts to copy data by evading the copy inhibited area.

Since the pre-address data is converted in the above-describeddisc-shaped recording medium 1, embodying the present invention, anaddress data error occurs when it is attempted to record original databy an unauthorized data recording apparatus, thus preventing illicitdata copying or illicit data modification.

The disc-shaped recording medium 1 can be manufactured by the masteringdevice 20 embodying the present invention. The mastering device 20 isable to convert pre-address data based on the pre-set conversion rule torecord the converted pre-address data on the disc-shaped recordingmedium 1.

In addition, data can be recorded on the disc-shaped recording medium 1by the data recording apparatus 40 embodying the present invention. Thedata recording apparatus 40 is aware of the conversion rule for thepre-address data recorded on the disc-shaped recording medium 1 andhence is able to decode the pre-address data in accordance with theconversion rule for the pre-address data to record data furnished withthe post address data in synchronism with the pre-address data on thedisc-shaped recording medium.

The present invention is not limited to the above-described embodiment.Although the foregoing description has been made on a recordable opticaldisc, on which no data has been recorded, such as DVD-R, DVD-RW,DVD-RAM, CD-R or CR-RW, as the disc-shaped recording medium 1, thepresent invention may be applied to other types of the recording mediumwithout limitation as to the disc type.

The present invention also is not limited to the above-mentioned firstto four methods as the pre-set conversion rule. Although the conversionis made on the sector address basis, it may be made on the block addressbasis.

The above-mentioned area 5 may encompass the entire area of thedisc-shaped recording medium 1, without being limited to only itspartial area. Thus, it is possible to have a portion of the lead-in area3 designed as routine pre-addresses and to convert the pre-addresses ofthe remaining area as described above. It is also possible to convertpre-addresses only for areas for recording the crucial information, suchas the control information indispensable for data reproduction,copyright information, information for decrypting the encrypted data orstart address information. That is, the present invention can bemodified within the purport of the invention as defined in the appendedclaims.

1. An apparatus for preparing a master disc of a recording medium onwhich digital data is recorded in synchronism with pre-recorded addressdata, said apparatus comprising: address generating means for generatingsaid address data; address conversion area designating means fordesignating an address data conversion area in accordance with a pre-setconversion rule; pre-format signal generating means for generatingpre-format signals pre-recorded on said recording medium, saidpre-format signals containing said address data; and recording means forrecording information specifying an area specified by said addressconversion area designating means as said pre-format signals from saidpre-format signal generating means on the master disc; wherein saidpre-format signal generating means converts at least a portion of saidaddress data in accordance with the pre-set conversion rule to generatesaid pre-format signals; wherein said pre-format signal generating meansincludes: address comparator means for comparing address data generatedby said address generating means with address data of an area specifiedby said address conversion area designating means; and addressconversion means for converting the address data generated by saidaddress generating means, in accordance with said pre-set conversionrule, based on results of a comparison by said address comparator means;wherein when, as a result of the comparison by said address comparatormeans, the address data generated by said address generating means isverified to be contained in the area specified by said addressconversion area designating means, said address conversion meansconverts the address data generated by said address generating means inaccordance with said pre-set conversion rule.
 2. The apparatus forpreparing a master disc according to claim 1 wherein said pre-setconversion rule is to record said address data in a decrementing order.3. The apparatus for preparing a master disc according to claim 1wherein said pre-set conversion rule is that, when all said address datato be converted among the pre-recorded address data is expressed with asame number of bits, information of bits corresponding to the same bitsof the address data to be converted is rewritten and recorded on saidmaster disc.
 4. The apparatus for preparing a master disc according toclaim 1 wherein said pre-set conversion rule is to record said addressdata upon conversion using pre-set key information.
 5. The apparatus forpreparing a master disc according to claim 4 wherein said pre-set keyinformation has been recorded on said master disc.
 6. The apparatus forpreparing a master disc according to claim 1 wherein at least one ofcontrol information used for reproduction of said digital data,copyright information, and information for decrypting encrypted digitaldata is recorded in an area in which said address data is converted inaccordance with said pre-set conversion rule.
 7. The apparatus forpreparing a master disc according to claim 1 wherein said pre-formatsignal generating means records said address data as pre-pits on saidmaster disc.
 8. The apparatus for preparing a master disc according toclaim 1 wherein said pre-format signal generating means records saidaddress data as embossed marks on said master disc.
 9. The apparatus forpreparing a master disc according to claim 1 wherein said pre-formatsignal generating means records said address data by wobbling a grooveformed on said master disc.
 10. A method for preparing a master discused for manufacturing a recording medium on which digital data has beenrecorded in synchronism with pre-recorded address data, said methodcomprising the steps of: generating said address data and designating anarea for conversion of said address data based on a pre-set conversionrule; comparing the generated address data with address data of thedesignated area; converting at least a portion of said address databased on the pre-set conversion rule when a result of the comparing stepverifies the generated address data is contained in the designated area;generating pre-format signals for recording on said master disc, saidpre-format signals containing said address data; and recordinginformation indicating the area for conversion of said address databased on said pre-set conversion rule as the generated pre-formatsignals on said master disc.
 11. The method for preparing a master discaccording to claim 10 wherein said pre-set conversion rule is to recordsaid address data in a decrementing order.
 12. The method for preparinga master disc according to claim 10 wherein said pre-set conversion ruleis that, all of the address data to be converted among the pre-recordedaddress data is expressed with a same number of bits, information ofbits corresponding to the same bits of the address data to be convertedis rewritten and recorded.
 13. The method for preparing a master discaccording to claim 10 wherein said pre-set conversion rule is to recordsaid address data upon conversion using pre-set key information.
 14. Themethod for preparing a master disc according to claim 13 wherein saidpre-set key information is recorded on said master disc.
 15. The methodfor preparing a master disc according to claim 10 wherein at least oneof control information used for reproduction of said digital data,copyright information, and information for decrypting encrypted digitaldata is recorded in an area in which said address data is converted inaccordance with said pre-set conversion rule.
 16. The method forpreparing a master disc according to claim 10 wherein said pre-formatsignal generating means records said address data as pre-pits on saidmaster disc.
 17. The method for preparing a master disc according toclaim 10 wherein said pre-format signal generating means records saidaddress data as embossed marks on said master disc.
 18. The apparatusfor preparing a master disc according to claim 10 wherein saidpre-format signal generating means records said address data by wobblinga groove formed on said master disc.